Floods are common in areas that do not have adequate drainage to handle a high influx of water. Unfortunately, whether an area is susceptible to flooding may change from year to year due to drainage changes as a result of construction, forest growth, river silting, and the like. Further, climate change has made the possibility of a “100 year” flood an event that can now happen in any given year. Unfortunately, it is not possible to predict how much water a flooding event will produce, for the flooding may be caused by upriver snowmelt or rain, locally heavy rainfall, high winds, and similar events that cause water stacking, a drainage malfunction, or the like any of which may cause flood waters to breech a building structure.
Flooding may not damage a building structure but it can be devastating on the contents within the building should water be allowed to enter the structure. The severity of the damage depends not only on the amount of water that accumulates within a building structure in a period of time, but also on the ability of the property owner to quickly remove the water within. Standing water of only an inch deep is sufficient to destroy the contents within the building structure should mold be allowed to take hold.
Most buildings are designed to keep out rain, but they are not necessarily designed to keep out flood water. The news channels are filled with pictures of a community banding together to save the building structures, if not the entire town, by the use of sandbags to redirect flood waters. If the pressure is substantially high or the water level is high enough then loads of water will seep past the sandbags and flood the area. The pressure exerted by the flowing flood water is the difference in water volume. The bigger the difference between the water volume across an area, the greater the force of the movement.
The potential for seepage within a building enclosure is so prevalent and difficult to prevent that the U.S. Army Corps of Engineers in Chapter 7, Section 701.1.1 of the U.S. Army Corps of Engineers ‘Flood Proofing Regulations’ has specified standards of performance and workmanship in Type 2 Closures in which they allowed “slight seepage” during hydrodynamic and hydrostatic pressure flood conditions in a Special Flood Hazard Zone.
The potential risks from a flood may be mitigated by taking the necessary steps such as causing the structure to resist the flooding. Flood proofing is a combination of adjustments and/or additions of features to individual buildings that are designed to eliminate or reduce the potential for flood damage. Flood proofing techniques can be classified on the basis of type of protection that is provided as follows: Type 1: permanent measures (always in-place, requires no action if flooding occurs); Type 2: contingent measures (requiring installation at the site when flooding occurs); and Type 3: emergency measures (improvised at the site when flooding occurs).
Emergency flood proofing measures include techniques that can be initiated on relatively short notice. Emergency methods to prevent flooding include sandbag dikes, stop log barriers, and earth-fill crib retaining walls. The primary advantage of an emergency method is the relatively low implementation cost. The principle disadvantage of emergency measures is that sufficient advance warning is required to mobilize personnel and install emergency barriers. Most emergency flood proofing methods require extensive labor force, depend on the availability of heavy machinery and trained operators on short notice, and necessitate a large amount of storage space. Furthermore, if the magnitude or the rate of the rise of a flood is misjudged the emergency flood proofing techniques fail. Not to mention aesthetically any emergency flood proofing measure is difficult to bear if left for long periods of time. Another disadvantage is that emergency measures do not satisfy the minimum requirements for watertight flood proofing as set forth by the National Flood Insurance Program for the protection of an existing construction.
Contingent measures such as flood shields and flood walls are watertight barriers designed to prevent the passage of water through doors, windows, or any other opening in a building structure exposed to flooding. Flood shields are usually installed only when flooding is imminent. Normally some type of gasket or seal is required to ensure that the shield is water tight. For example, U.S. Pat. No. 5,943,832, “Flood or Storm Resistant Barriers for Doorways or Window Opening” discloses a frame having two parts, one of the frame parts having portions in telescopic engagement with the other frame part, and a manually operable jack mounted between the two frame parts and operable to move the two frame parts relative to one another to vary an external dimension of the frame and thereby enable the frame to be secured in a doorway or window opening by expansion of the frame into engagement with opposed surfaces of the doorway or window opening. However, the operable jack is exposed to the elements and susceptible to corrosion; this device requires proper maintenance to insure integrity.
U.S. Pat. No. 3,796,010 entitled “Pneumatically Sealable Flood Panel Assembly” discloses a flood panel assembly for installation in doorways to improve water-tight integrity under moderate flood conditions comprising of a conversion frame structure permanently installed into the access opening, and a removable panel arranged to be inserted in the conversion frame and arranged to establish a water-tight association with the conversion frame. The removable flood panel is provided about its edges with an inflatable sealing element, which is normally in a deflated condition. When the flood panel is installed in the conversion frame, it is initially locked in position and the sealing element is thereafter inflated, causing it to expand and provide a water-tight seal. Unfortunately, these flood shield devices are expensive, proper storage is required, and tools are needed for proper installation.
Movable floodwalls consist of a flood barrier which is hinged along the bottom so that it can be lowered to a horizontal position to fit flush with existing ground or pavement. For instance, U.S. Pat. No. 5,077,945 “Doorway Flood Barrier” discloses a doorway mounted flood barrier including a barrier wall having two opposite vertical side edges and a horizontal bottom edge, and retainer means disposed between the barrier wall and lower portion of the doorway for holding the barrier wall sealingly in the lower portion of the doorway. Again, movable floodwall devices are expensive and require proper maintenance.
Permanent flood proofing measures include closures and sealants, and floodwalls and levees. Permanent floodwalls and levees measures are alternatives for protecting a large area or a number of structures, they can be a practical and economical flood proofing technique for protecting single or small groups of structures.
Permanent closure and sealant measures basically involve filling an existing window or opening with some form of water-resistant material such as concrete or sealant. A sealant is a water proof coating that can be applied to the outside of an existing wall to eliminate the wall's permeability. This coating is generally an asphalt-based or polymeric compound that can be painted or sprayed onto the wall. For example, the amount of pressure exerted on a window pane during a flood may be a load the window pane cannot handle. The breached window pane provides a point of entry for wind or water whereby the water enters the building structure and causes severe damage to the infrastructure of the home, upholstery, and furniture and eventually causing sever molding. Therefore, it takes the entire window system to make a seal proof opening within the window cavity. The impact resistant window pane may provide protection from wind, missiles, debris, and water against the window pane but if the frame is not properly installed a load could hit the window pane and cause the entire frame to come off the retaining wall defining a window cavity. Aside from the window pane and frame being susceptible to being struck or blown in by flood water, the gap between the window frame and the retaining wall is especially vulnerable.
Water seeping into the building structure through the area between the frame and retaining wall in which it was installed presents a glaring problem. Caulking is typically performed with a material such as silicone, polyurethane, or polysulfide and is used in filling the gap between the retaining wall and the window frame to eliminate permeability. Caulk has a limited life which is further shortened upon exposure to the elements such as UV light. Caulk that has degraded may become a brittle and lack any ability to prevent water from entering the space between the frame and the structure. Caulk that has minimal shrinkage may appear capable of preventing water passage, however, the shrinkage may create a latent condition wherein the failure occurs when a seal is most important.
Caulk is particularly susceptible to environmental temperature as it expands and contracts leaving potential openings within the gap. During a flood, water pressure builds up on the window frame and if the caulking is brittle the water pressure may be such that it surges pass the caulking and enters the building structure.
U.S. Pat. Nos. 2,497,515, 2,504,204, 3,500,603, 3,694,984, 6,895,718 and U.S. Published Application Nos. 2002/0139060, and 2006/0087114 disclose different methods and compounds for sealing windows and other building structures from the intrusion of water and other undesired elements. U.S. Pat. No. 5,722,207 discloses a metal nail fin or flashing for mounting a window in an opening. U.S. Pat. No. 6,253,796 discloses a gutter retainer.
While these prior art techniques may be suitable for the particular purpose to which they address, they do not present a method of inhibiting flood water entry into a structure about a window frame.